College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
J Chem Phys. 2013 Nov 14;139(18):184701. doi: 10.1063/1.4828861.
A theoretical study is conducted to search for Dirac cones in two-dimensional carbon allotropes with square symmetry. By enumerating the carbon atoms in a unit cell up to 12, an allotrope with octatomic rings is recognized to possess Dirac cones under a simple tight-binding approach. The obtained Dirac cones are accompanied by flat bands at the Fermi level, and the resulting massless Dirac-Weyl fermions are chiral particles with a pseudospin of S = 1, rather than the conventional S = 1∕2 of graphene. The spin-1 Dirac cones are also predicted to exist in hexagonal graphene antidot lattices.
进行了一项理论研究，以在具有正方形对称性的二维碳同素异形体中寻找狄拉克锥。通过列举最多 12 个单元胞中的碳原子，在简单的紧束缚方法下，识别出具有八原子环的同素异形体具有狄拉克锥。所得到的狄拉克锥伴随着费米能级处的扁平能带，并且由此产生的无质量狄拉克-外尔费米子是手性粒子，其赝自旋 S = 1，而不是传统的石墨烯的 S = 1∕2。还预测在六方石墨烯缺陷格子中存在自旋-1 狄拉克锥。
